Oh dear!
This sounds familiar
I had an adopted child too - and he was strange in ways that did not reveal themselves to me until after my biological child was born two years later
She was a premmie and came home when she was four weeks old - and the adopted P came to us when he was only two weeks old
And I will never forget that high-pitch angry wail that go on for hours
He thrived
All he did was scream - suck - and sleep and I'd look at him in his bassinet and think
"You're really beautiful but there's something wrong with you"
My doctor told me that there are some babies that make everyone's life hell for months - he kept it up for 16 years.
What I can tell you about the adopted infant's scream is something you've probably felt yourself - and yet maybe not had a name for your feeling or even had anyone else acknowledge it
I called it "The Unknown Other" - and I would see people struggling with him - teachers, social workers, doctors, finally his probation officer.
I was in court - and I saw the probabion officer struggling to explain my son's attitude and behaviour under oath - and by chance my then-husband and I went home and this guy was stumped
He understood there was something else no one understood
But I had some good emails from the manager of a group called "Adoptese" who told me that the unknown other is the adopted child's birth mother
No wonder so many adopted people get angry
If I can help you out at all - with more info than I can post atm - please let me know
Sparky